help me identify these books please?

i have two books in mind. i read them when i was 11 or 12. i vaguely remember some details but i cannot piece them together to identify the books. please help:

first book: it was thin, with a blue spine and back. cover illustration was a black and white close up photo of a rose. it was a murder mystery book. first person writing if i am not wrong. the story opens with the detective describing himself as unattractive, middle aged and balding.

second: i remember it was called meredith. i could be wrong. it was about 2 sisters. one sister is a ballerina who invited her dad to some ballet even in the early chapters but was embarrassed because he was wearing a cheap brown (or blue) suit with leather patches on the elbows while the other ballerina's dads were looking sleek in black suits. the ballerina's sister is involved in some cult or something and does creepy rituals like walking around a bon fire naked.

ok i know the details seem random. but i really hope to identify these books. thanks =]