orlando fla. orlando nightclub killer omar mateen express sympathy variety islamist extremists include group middle east swear enemies fbi say monday picture begin emerge angry violent man carry america deadly mass shoot u.s. authorities say find direct link islamic state mateen u.s.-born son afghan immigrants kill 49 people gay nightclub orlando sunday mateen 29 shoot dead police storm pulse club armor cars three-hour siege 911 call rampage killer express allegiance islamic state leader abu bakr al-baghdadi federal bureau investigation director jam comey say mateen make comment favorable multiple arm islamist movements people add little bite confusion motives president barack obama say mateen likely homegrown extremist far see indication plot direct outside unite state see indication part kind network comey tell reporters washington highly confident killer radicalize least part internet islamic state control territory iraq syria reiterate monday claim responsibility although offer sign indicate coordination gunman call authorities sunday mateen also mention support boston marathon bombers florida man become nusra front suicide bomber syria comey say nusra al qaeda offshoot odds islamic state syria civil war co-workers report mateen fbi 2013 make inflammatory contradictory statements include claim family connections al qaeda membership shi ite militant group hezbollah bitter rival fbi miami office investigate mateen 10 months interview twice find evidence crime connection militant group comey say fbi also work understand role anti-gay bigotry may play attack massacre reverberate presidential campaign trail republican donald trump democrat hillary clinton two likely opponents nov. election clash confront violent islamist extremists trump propose suspend immigration unite state countries history terrorism america europe u.s. ally clinton warn demonize muslims call tough gun safety measure obama visit orlando thursday pay respect families victims orlando kill follow massacre 14 people san bernardino california last year raise question whether unite state confront jihadist attack homeland years come comey say track apparent lone wolf attackers like mateen like find needle nationwide haystack also try work kind people could become radicalize florida shoot spree begin early sunday club pack 350 revelers latin music night many flee gunman rake crowd bullets ar-15-style semiautomatic rifle pistol initial wave officer charge club trap mateen bathroom orlando police chief john mina tell reporters allow many patrons flee although others trap restroom mateen lead standoff police negotiate mateen three hours break hole wall allow hostages escape mateen also emerge hole shoot dead officer police say 53 people wound 29 remain hospitalize orlando regional medical center michael cheatham chief trauma surgeon hospital tell fox news expect survivors hospital survive amanda alvear last snapchat video post begin shoot dance floor nightclub surround friends end gunshots ring music alvear 25 identify police one kill pulse friend mercedez flores 26 work target also list another victim edward sotomayor 34 market manager florida-based gay-themed travel company legend industry boss al ferguson say pastor deyni ventura visit survivor hospital identify norman take refuge handicap bathroom stall cram 30 people norman could hear shooter laugh loudly spray gunfire bathroom stall see shooter could hear laugh ventura say intimate loud cackle laugh norman shoot four time crawl body friends safety everyone else stall die ventura say people fatally shoot latino half puerto rican origin least three mexican citizens hundreds people attend vigil monday night dead downtown orlando law enforcement officials search clue whether anyone work mateen attack say lee bentley u.s. attorney middle district florida officials say believe attackers evidence threat public mateen ex-wife sitora yusifiy describe mentally unstable violent toward would get mad nowhere start worry safety months start abuse physically often tell reporters couple split 2009 four months marriage mateen meet father day kill betray nothing rage would soon erupt notice anything wrong seddique mateen say interview slick close-knit muslim community 100 families fort pierce florida mateen know quiet friends people person extremely friendly rude either say mohammed jameel 54 worship mosque mateen arm guard gate retirement community work global security firm g4s gfs.l nine years .. tell fbi investigation make pro-islamist remark angry co-workers felt discriminate tease muslim comey say orlando killer express support multiple islamist group