My best friend recently dated a policeman. Very weird situation! Bear with me as it's long.
Best friends DP left her after 5 years together. She was heartbroken and didn't leave her house for a month. She then joined Tinder to try and 'get back out there'. Met a lovely-sounding guy, about 8 years older, policeman. They talked for a few weeks and he seemed kind and hardworking, said he was looking for 'the right girl to take things slow with'. He invited her to his house for drinks in the garden. I dropped her off so I knew where she was and she was texting me updates. Started off nice, then it became clear he was a massive drinker/borderline alcoholic - he drank a crate of beers within a few hours while she'd had 2 G&T's. She then went inside to use the loo and he followed her inside, started being very flirty and suggestive. My friend said she didn't particularly fancy him but just needed a bit of a a rebound and was v depressed after her breakup, so went for it. They ended up sleeping together. He passed out straight after and she got an Uber home as she felt a bit uncomfortable and didn't really want to wake up there. He didn't contact her for 2 days.
2 days after that she found out she was pregnant, not his baby obviously, but her exes(!) - she text him to apologise and told him she'd found out she's pregnant and needs to make some choices before she starts dating again. He bombarded her with calls and kept asking her to come round, said 'pregnant ladies are sexy to me' and 'i want to support you and the baby'. She blocked his number. He contacted her on 3 different numbers. After about 10 days just as she was about to report him this finally stopped.
She didn't think of him again except the weird and slightly creepy 'date', then she had her booking in apt with the midwife and told midwife she'd been having some strange symptoms. Midwife sent her to GUM clinic and she found out this guy had given her Chlamydia!
She unblocked him and rang him to let him know he has Chlamydia and to let any other sexual partners know. Apparently his response was 'bloody hell, well it's obviously come from you, I've only slept with 5 people this month' 
Safe so say she's learned a lot of lessons! She's now clear of STI's and heavily pregnant, happily single. And I wouldn't go near a policeman after this!